AWS Cognito：如何以编程方式删除身份？

Question

In my Android app, I use AWS Cognito to allow my users to sign up and login. I configured my identity pool so it allows guest users (unauthenticated users) in my app.

So everytime my user logs in or logs out, I call the following code to get an identity ID:

CognitoCachingCredentialsProvider credentialsProvider = new CognitoCachingCredentialsProvider(
    this,
    "eu-central-1:12345678-1234-5678-9012-1234567890ab",
    "eu-central-1");
credentialsProvider.clearCredentials();
credentialsProvider.getIdentityId();

When my user logs in, it creates a new identity the first time, then the user gets the same identity everytime he logs in. But everytime he logs out, a new identity is created, since he's now a "guest" user.

Is that the expected behavior? And if yes, how can I remove an unused identity programmatically (for example when the user logs in, so the "guest" identity is now useless, since a new one will be created when he logs out)?

Thanks for your help.

Answer 1

From the docs, we have:

getIdentityId() Gets the Cognito identity id of the user. The first time when this method is called, a network request will be made to retrieve a new identity id. After that it's saved in SharedPreferences.

clearCredentials() Destroy all the saved AWS credentials but not the identity Id.

so, the behavior you described is totally normal according to the docs.

Now, let's find an approach to deal with the problem.

if you want to continue with your proposition, and delete the identity programmatically after the logout, you can use deleteUser() method from AWSJavaSDK.

However, if you want to keep the same identity for the same user after the logout, you shouldn't clear the cache, cause the won't keep the user any trace of its identity.

I hope this will help.